Ascorbic wheat

For wheat plants grown to maturity under irrigation (43) in a soil of neutral pH (44), one can calculate that a mature wheat plant (yield 13.2 g d m [grams of dry matter)] with a Mn concentration of 42 mg/kg took up 556 pg of Mn [i.e., (556/55) X 2 microequivalents of Mn], If ascorbic acid (M, a = 176), or another reducing agent of similar molecular weight and C content is assumed to be the... 

Grosch, W., Wieser, H. 1999. Redox reactions in wheat dough is affected by ascorbic acid. J Cereal Sci 29 1-16. 

De Gara, L., de Pinto, M. C., and Arrigoni, O., 1997, Ascorbate synthesis and ascorbate peroxidase activity during the early stage of wheat development. Physiol. Plant. 100 894n900. 

Meneguzzo, S., Sgherri, C. L. M., Navari-lzzo, F., and Izzo, R., 1998, Stromal and thylakoid-bound ascorbate peroxidases in NaCl-treated wheat. Physiol. Plant. 104 735n740. 

As noted above, ascorbic acid can sometimes cause immune reactions. Ascorbic acid and citric acid are used as food additives, ascorbic acid (E300) as an acidifier, an antioxidant, and an additive in wheat, and citric acid as an acidifying complex-binding agent. Because additives are widely used in foods, beverages, and drugs, people with allergies or intolerance have to be carefully instructed. Caution must also be taken when scratch tests are performed with these substances (34). 

Abrol et al. (637), reporting on the darkening of whole wheat meal, due to the action of tyrosinase in bran, found added ascorbic acid (0.5-2.0 mg/kg) to retard the darkening effect. In another context, durum and other wheat granular flours (semolina) require retention of their natural yellow carotenoid content for the manufacture of pasta products which Dahle (638) and Walsh et al. (639) observed were stabilized by added L-ascorbic acid. 

Wheat germ oil was studied in similar experiments, and it rapidly forms peroxides (Table V). Ascorbic acid and AP were more efficient antioxidants here than was BHT. To investigate the effect on wheat, whole berries were added to water and mixed with 0.1 g of antioxidants/ 100 g of berries and then dried at 60°C overnight. The dried mass was pulverized in a Waring blender and 10 g was added to petri dishes and titrated daily for peroxide after extraction into chloroform-acetic acid. 

Baked whole-wheat bread Ferric ammonium citrate and ascorbic acid added before cooking No iron or ascorbic acid added Less Intrinsic- extrinsic (human) 24... 

Nakamura, M. and Kurata, T. Effects of L-ascorbic acid on the rheological properties of wheat flour dough. Cereal Chem., 74, 647, 1997. 

A microsomal type b cytochrome with the a peak at 559 nm is called cytochrome bs (276,277,278). The molecular weight of cytochrome bs obtained from Vida faba leaves (279,280) is 28,000. This preparation is reduced by ascorbic acid and does not combine with CO. The Eo of wheat-root cytochrome 63 (o band 559 nm), which is identical with or very similar to microsomal cytochrome 63, is reported to be -j-40 mV... 

The ascorbic acid is oxidized by ascorbic acid oxidase in the flour dough to dehydroascorbic acid. In turn, the reduction of dehydroascorbic acid is coupled with the oxidation of protein thiol groups by the enzyme dehydroascorbic acid reductase known to be in wheat (133). 

ACC oxidase shows an absolute requirement for oxygen, Fe and ascorbate, and is activated by carbon dioxide but not by bicarbonate [100]. Except for the requirement for ascorbate, other properties were established for EFE activity detected at the tissue level. Illumination apparently inhibits EFE in green wheat leaves, but this inhibition was later found to be due to decreased carbon dioxide caused by active photosynthesis in light... 

Lesko K, Steeanovits-Banyai fi, Pais 1 and Simon-Sarkadi L (2000) Effect of cadmium and titanium-ascorbate stress on polyamine content of wheat seedlings. Mengen- und Spurenelemente 20 819— 824. 

Following the same study design, 11 healthy infants (5 boys and 6 girls, 18-27 weeks old and weighing 5.5-8 kg) received an infant cereal (based on wheat flour and soy flour) fortified with 2 mg Fe from either radiolabelled sodium iron EDTA or iron(ll) sulfate, the latter plus added ascorbic acid (to optimize conditions... 

---